linux网络设备—mdio总线

一.结构体

struct mii_bus {

	const char *name;	//总线名

	char id[MII_BUS_ID_SIZE];	//id

	void *priv;	//私有数据

	int (*read)(struct mii_bus *bus, int phy_id, int regnum);	//读方法

	int (*write)(struct mii_bus *bus, int phy_id, int regnum, u16 val);	//写方法

	int (*reset)(struct mii_bus *bus);	//复位

	struct mutex mdio_lock;

	struct device *parent;	//父设备

	enum {

		MDIOBUS_ALLOCATED = 1,

		MDIOBUS_REGISTERED,

		MDIOBUS_UNREGISTERED,

		MDIOBUS_RELEASED,

	} state;	//总线状态

	struct device dev;	//设备文件

	struct phy_device *phy_map[PHY_MAX_ADDR];	//PHY设备数组

	u32 phy_mask;

	int *irq;	//中断

};

二.初始化过程

在phy_init函数中调用了mdio_bus_init初始化mdio总线

int __init mdio_bus_init(void)

{

	int ret;

	ret = class_register(&mdio_bus_class);	//注册设备类

	if (!ret) {

		ret = bus_register(&mdio_bus_type);	//注册mdio总线

		if (ret)

			class_unregister(&mdio_bus_class);

	}

	return ret;

}

设备类"/sys/class/mdio_bus"

static struct class mdio_bus_class = {

	.name		= "mdio_bus",

	.dev_release	= mdiobus_release,

};

总线类型"/sys/bus/mdio"

struct bus_type mdio_bus_type = {

	.name		= "mdio_bus",

	.match		= mdio_bus_match,	//匹配方法

	.pm		= MDIO_BUS_PM_OPS,

};

EXPORT_SYMBOL(mdio_bus_type);

三.mdio总线注册
1.调用mdiobus_alloc函数分配内存

struct mii_bus *mdiobus_alloc(void)

{

	struct mii_bus *bus;

	bus = kzalloc(sizeof(*bus), GFP_KERNEL);	//分配内存

	if (bus != NULL)

		bus->state = MDIOBUS_ALLOCATED;

	return bus;

}

EXPORT_SYMBOL(mdiobus_alloc);

2.填充mii_bus的结构体成员

mii_bus->name 	= ;

mii_bus->read 	= ;

mii_bus->write	= ;

mii_bus->reset	= ;

mii_bus->parent	= ;

mii_bus->priv 	= ;

mii_bus->id	= ;

3.注册mii_bus

int mdiobus_register(struct mii_bus *bus)

{

	int i, err;

	if (NULL == bus || NULL == bus->name || NULL == bus->read ||NULL == bus->write)

		return -EINVAL;

	BUG_ON(bus->state != MDIOBUS_ALLOCATED &&bus->state != MDIOBUS_UNREGISTERED);

	bus->dev.parent = bus->parent;

	bus->dev.class = &mdio_bus_class;	//总线设备类"/sys/bus/mdio_bus"

	bus->dev.groups = NULL;

	dev_set_name(&bus->dev, "%s", bus->id);	//设置总线设备名

	err = device_register(&bus->dev);	//注册设备文件

	if (err) {

		printk(KERN_ERR "mii_bus %s failed to register\n", bus->id);

		return -EINVAL;

	}

	mutex_init(&bus->mdio_lock);

	if (bus->reset)

		bus->reset(bus);	//总线复位

	for (i = 0; i < PHY_MAX_ADDR; i++) {

		if ((bus->phy_mask & (1 << i)) == 0) {

			struct phy_device *phydev;

			phydev = mdiobus_scan(bus, i);	//扫描phy设备

			if (IS_ERR(phydev)) {

				err = PTR_ERR(phydev);

				goto error;

			}

		}

	}

	bus->state = MDIOBUS_REGISTERED;	//状态设置为已注册

	pr_info("%s: probed\n", bus->name);

	return 0;

error:

	while (--i >= 0) {

		if (bus->phy_map[i])

			device_unregister(&bus->phy_map[i]->dev);

	}

	device_del(&bus->dev);

	return err;

}

EXPORT_SYMBOL(mdiobus_register);

调用了mdiobus_scan函数

struct phy_device *mdiobus_scan(struct mii_bus *bus, int addr)

{

	struct phy_device *phydev;

	int err;

	phydev = get_phy_device(bus, addr);	//获取创建phy设备

	if (IS_ERR(phydev) || phydev == NULL)

		return phydev;

	err = phy_device_register(phydev);	//注册phy设备

	if (err) {

		phy_device_free(phydev);

		return NULL;

	}

	return phydev;

}

EXPORT_SYMBOL(mdiobus_scan);

动态地创建了PHY设备

四.mii、mdio、phy、mac关系图

巴特西

linux网络设备—mdio总线

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